Thus, it is argued that smoking should be made prohibited in public places such as bus and railway stations. This position will be proven by looking at how this arrangement has benefited both general public as well as smokers.
Well, your prompt has asked you -
Do you agree or disagree with this statement?
.... this is more direct and asks you about your opinion. So, you too should express your view on that directly without making general and vague statements. Tell that you agree with the view if you do, otherwise say you don't agree.
I have provided you a good approach for your intro in one of your other threads. Hope it would help you polish your approach for intro :)
To start, non-smoking public would be undoubtedly benefited by enforcing such restrain. Prior to 1980's public places in Sri Lanka, illustrates unpleasant situation where people smoked freely. Even in public transportation they engaged in this intolerant bad habit, some instances that lead to belligerent incidents. After enforcing restrictions the situation came to control and this act as benefit rendered to the public.
Very good body para :) Glad to meet a Sri Lankan here in this forum. I am too from SL :) ...
You write very well - use the direct speech more in your writing :)